A comparative study of the chromosomes from five species of the genus Rana PublicDeposited

Descriptions

The karyotypes of five species of ranid frogs were determined
from metaphase plates of bone marrow cells. The colchicine, hypotonic-
citrate, blaze-dry technique was used to obtain the plates.
Morphometric datawere obtained from the karyotypes and compared
with other species of the genus Rana.
Like most other members of the genus Rana, the five species
examined in this study have 26 chromosomes. These can be divided
into a group of five large pairs and a group of eight small pairs.
Relative chromosomal length is similar in all species. However,
differences are apparent. Rana aurora has more metacentric chromosomes
than the other species. R. cascadae has one pair of subtelocentric
chromosomes and R. muscosa has three pairs of telocentric
chromosomes.
Comparisons of chromosomal arm ratios confirm the present
taxonomy of the species. R. cascadae is more similar to R. pretiosa
than to R. aurora. R. boylii and R. muscosa can be separated from
the other three by two pairs of chromosomes.